Audi A5 e-tron Quattro -- A new take on plug-in hybrid tech

The latest addition to the ever-expanding Audihybrid/electric developmental portfolio, the A5 e-tron Quattro serves up an intriguing drivetrain alternative -- and one that many feel has a real shot at becoming production-ready in a fairly short time interval. Unlike typical Quattro configurations, the one in this particular one-off dispenses with the center differential and associated rear mechanical linkages, replacing it with a separate electric motor mounted on the aft axle.

Primary power for the Audi A5 e-tron Quattro comes from the automaker’s ubiquitous 2.0-liter TFSI turbo four-cylinder that makes 208 horsepower paired with an electric motor that adds 44 ponies of its own. All of this output gets shipped to the front wheels via a four-speed automatic transmission, although the specific source of the motivation varies depending on vehicle speed and driving conditions. The trick bit of this Quattro setup is found at the rear, where a second electric motor/generator can add an additional 81 on-demand horses to the mix and bring the total system output to 314 horsepower. It’s integrated with a differential that provides the same kind of torque-vectoring capability as the current production Audi Sport Differential. Both motors get their power from a 9.4kW lithium-ion battery pack optimally positioned where the driveshaft normally would be located.

Although largely aluminum, the experimental Audi A5 e-tron Quattro concept uses a variety of lightweight materials including carbon-fiber reinforced plastic to help keep its curb weight about the same as a production A5 Quattro. According to Audi, it can operate at speeds of up to 62 mph and travel up to 25 miles in EV-only mode, accelerate from 0-62 mph in 5.9 seconds and top out at 142 mph. Near-instantaneous transitions from front- to all-wheel drive occur under maximum acceleration conditions or whenever the system senses rear-wheel slippage. While a super-efficient regenerative braking setup handles on-the-fly charge boosting of the Audi A5 e-tron Quattro battery, plug-in replenishing takes about two hours on a 230-240V line.